Macro stack_pop 

macro_rules! stack_pop {
    ($stack:expr, $data:expr) => { ... };
    ($stack:expr, $data:expr, $amount:expr) => { ... };
}

Alternative to stack.pop(&mut data). Use stack_pop!(stack, data) Or stack_pop!(stack, data, 3) 3 being the amount of states to pop. OBS.: Don’t use &mut data as a parameter, but simply data.

• Accepts an amount of times to pop.